Don't waste it. Empty hours (like netflix hours and laying in bed hours) are wasted hours. They're like empty calories: they feel good in your throat, but shitty on your waste.
2) Junk food makes you feel like shit. Eat healthy foods exclusively. Let chocolate do infrequent cameos when you're feeling down.
3) Exercise feels good; if not at first then after two weeks of practice when it all starts to come together. You don't HAVE to follow a routine. You don't HAVE to work out only in the mornings. Do what you want when you're ready to do it.
4) Don't feel bad or guilty when you mess up. People don't really care if you stutter a bit or if you sometimes mishear them. Don't freak out. Your entire existence doesn't hang in the balance of any single conversation.
5) That said, don't be afraid to talk about the good things about you either. It's not really bragging, and it's more fun to hear about someone's good times than about how shitty they feel or what their problems are. It's OK to say nice things about yourself. Don't be defensive, just be real.
6) You're worth also isn't determined by your grades. Obviously having good grades is great, but if you mess up, it's OK. If something isn't perfect, it doesn't mean that you aren't perfect. Be calm when writing your papers. Just work hard and be calm.
7) Life isn't a competition. If someone else does better, or graduates first, or has a perfect relationship it's not about you, it's about them. They aren't comparing themselves to you and you shouldn't either.
You can only do what you can do. Keep pushing forward so that you can do more.